Self-healing capacity

Recently, fly ash (from coal combustion) was identified as a suitable alternative alkaline material because of its low-cost, local availability, and self-healing capacity (Perez-Ldpez et al. 2007a). Fly ash prevents AMD generation in two ways (1) over short periods, fly ash increases pH, resulting in the precipitation of Fe oxyhydroxide... 

Pin-on-disk experiments on fiuorescently labeled PLL-g-PEG films suggest that the tribo-stress-induced desorption of the PLL-g-PEG films is mainly due to the removal of complete molecules rather than their partial removal. In the presence of sufficient concentrations of free polymer in the solution, a replacement of the desorbed polymer was observed. This self-healing capacity is assumed to be the reason for the enhanced resistance to abrasion that we observed with PLL(20)-g[3.5]-PEG(2) in the presence of excess polymer in the solution. 

Xu et al. have reported a GO/DNA hydrogel with high mechanical strength, excellent environmental stability, high dye-adsorption capacity, and self-healing function... 

The fundamental belief in the capacity of the human psyche to be self-healing under the proper circumstances is but one of the many striking parallels between Dr. Hausner s conclusions and those of the group at the Maryland... 

Plasticized polymer films are known to possess an unusual property of self-healing. Their sealing capacity is not impaired noticeably even by 100 pm diameter punctures. The data presented in Fig. 2.59a prove that the electrolyte (0.1 N solution of HCl) cannot penetrate through the PE film plasticized by the mineral oil even in the presence of puncture defects and the effect of mechanical vibration. Testing of a plasticized PE film has shown... 

In addition, there is also the possibility of tailoring the properties of plain composites further by adding particles (such as metallic fillers [29,30], carbon nanotubes [31] or urea formaldehyde [32]) to the composite layers to create multifunctional and self-healing materials, von Klemperer and Maharaj [29] added copper and aluminium powder fillers to carbon fibre epoxy laminates to improve the electromagnetic shielding capacity of the composite panels. Blast tests on the laminates [30] showed that the laminates with filler particles outperformed their plain composite counterparts, although the margin was small. 

Of primary importance to both tissues is their structural organization and self-repair capacity. However, once they are injured by critical-sized lesions, healing is often inadequate and functional recovery becomes suboptimal. In such scenarios, bioresorbable materials offer remarkable opportunities to restore the native tissues or replace them with engineered substitutes. 

In addition, composite systems can be manufactured with smart materials to identify damage and lead to self-healing or even self-cleaning mechanisms [8]. Composite applicahons are not limited to new structures, as they can be utilized to rehabilitate or upgrade existing structures for safety or to increase load-carrying capacity. A few of these aspects are briefly described in the sections given later. 

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